User task physical writes: <count>
Modified pages can be displaced from the data cache to the data area, because not all of the data used by the applications can be held in the data cache.
If the size of the data cache is sufficient, the physical writing is delayed until the next Savepoint and then be done asynchronously. Cache displacements, however, use synchronous writes and reads, and should be avoided if possible.
This phenomenon is almost unavoidable if load times (data import) are long, since the volume of imported data is usually much larger than the size of the data cache.
Increase the size of the data cache.
Concepts of the Database System, Working Memory Areas